Services Provided by Kerelaw
We undertake specialist investigative building surveys using modern techniques utilising electronic moisture meters and where possible low disturbance techniques using fibre optical scopes and chemical analyses to determine the extent and cause of building defects and to provide remedial recommendations.
TREATMENTS CARRIED OUT
Visual survey Inspection
When you contact Kerelaw Building Preservation to instruct a Timber and Damp Survey on the condition of your property you are putting your trust in our representative who is going to survey your house, identify the problems and make recommendations to implement any remedial treatments necessary and you are putting your trust in our company to undertake those works.
You want to be confident that the advice and recommendations you are given are honest and based upon detailed observations, correct diagnosis and the remedy and recommendations appropriate to the building and your interests.
When observing a structure our surveyor may make a judgement about a certain problem or aspect of a problem in relation to several issues within areas that cannot be inspection due to lack of access at the time of inspection.
Judgements will be categorised as essential or recommended work, this presents you with a choice as to which approach to adopt. There may also be areas which could not be inspection due to the presence of floor coverings, fitted furniture and other obstacles and for this reason it is important to discuss these issues with our surveyor for your own clarity and peace of mind.
Our report will identify visual areas where defects were noted, our surveyors will test walls with an electronic moisture meter, all accessible roof spaces will be inspected, floors will be weigh tested under foot and where available loose carpets uplifted to inspect leading edges of flooring at outer walls, external inspection will determine any potential areas where water may ingress the property, rain water goods, chimneys and flashings will be observed from ground level to determine any potential signs which may lead to damp related problems, which may be undetected internally. A quotation will be provided for any remedial treatments recommended.
Moisture Meter Testing
The electrical resistance and capacitance meter is easy to use and provides rapid results. This is a non-destructive technique, used on the surface of building components, by pressing the probes or capacitance pad against the building material provides an immediate moisture content reading.
The meter is usually calibrated for timber components, giving very accurate results when used in timber. When used with other building materials, such as plaster or brickwork, some calibration of the moisture scales supplied may be necessary as readings are not then referred to a moisture content percentage but high medium or low.
Care is needed in interpreting the results; the electrical resistance method generally provides an indication of surface moisture, This surface reading may not be representative of the overall moisture content of the component. In addition, naturally occurring mineral salts, timber preservatives and embedded metals can affect the electrical resistance of the material and subsequently the measured moisture content.
The resistance meter method is particularly useful for looking at changes in moisture content. When looking at the drying-out of a building after wetting, the absolute moisture level may not be of particular importance as it may be exceptionally high. However, when the moisture content results are compared over time, it is the regular drop in moisture content that is important. The electrical resistance meter is a particularly useful tool for keeping records and monitoring the rate at which moisture content is reducing or changing.
Contaminated Salt Analysis
Salt analysis is an important diagnostic aid. The presence of chlorides and nitrates in plaster samples can confirm rising damp. The presence of salts can cause crystallisation and interaction with relative humidity and water vapour can lead to the cyclical deliquescence of salt crystallisation back to moisture.
Hygroscopic salts are indicative of rising damp and are one of the reasons for removal of plaster and reinstatement with salt retardants.
Thermal Imaging Camera
Infrared Imaging can be a very effective as non-intrusive building diagnostic procedure when used professionally for appropriate applications.
How Infrared Imaging Works
The outer skin of any object absorbs thermal energy from its surroundings. A building obtains thermal energy from the sun, atmosphere, and human activity. This energy is emitted as thermal radiation, which can be measured by an Infrared Imaging camera.
If the specific properties of a material are known, an Infrared Camera can give accurate temperature measurements across its surface. In the context of dwellings, building professionals use Infrared imaging to observe spatial temperature variation i.e. patterns. This enables them to identify conditions or events they wish to eliminate, isolate or confirm.
Uses of thermal imaging systems
Identify structural defects that create thermal bridges so that these sources of thermal discomfort and condensation problems can be removed or managed
The system can also be used to ensure building fabric has dried following flooding, And identify areas contaminated with hygroscopic elements
It can be used to identify and isolate roof defects to allow effective repairs and avoid expensive early replacement of roof elements.
Pinpoint areas that need repair e.g. concrete delamination and therefore reduce man-hours spent on preventive maintenance and defect identification.
Evaluate and verify repair work, which ultimately gives peace of mind for repairer and their customer.
Often Called A Speedy Meter after the manufacturer.
Calcium Carbide testing is conducted in a sealed pressure vessel using a weighed sample of masonry preferably from the mortar joint extracted from above the damp proof course.
The sample is mixed with a precise measure of calcium carbide powder and inserted in the vessel. This is shaken vigorously and the meter on the bottom provides a reading 0 – 5 – the higher the reading the more moisture is present. The results of this test are very reliable and the meter can often be used to confirm or negate the presence of moisture.